Unsaturated polyesters and polyamides are two classes of materials useful in the fabrication of a wide variety of products. By varying the starting monomers, some can be made spinnable into fibers and filaments; some are useful in casting; some are moldable; still others can be formulated into coatings. The physical and chemical properties can be changed through choice of monomers, polymerization procedures and other means. None are without one or more deficiences, however.
More recently, a class of polyesteramides has been developed. Basically, those materials have been the random interpolymerization of a dicarboxylic acid with a diol and a diamine. The products have exhibited a spectrum of properties substantially different from either polyesters or polyamides.
Also recently, polyesters have been modified with dicyclopentadiene to result in products having reduced shrinkage upon curing, enhanced hydrophobicity and better economics than the corresponding unmodified polyesters.
Although all of those materials have been useful in making products acceptable in the marketplace, there is room for considerable improvement in many of their properties.